kernel/uid16.c

   1 /*
   2  *      Wrapper functions for 16bit uid back compatibility. All nicely tied
   3  *      together in the faint hope we can take the out in five years time.
   4  */
   5
   6 #include <linux/mm.h>
   7 #include <linux/utsname.h>
   8 #include <linux/mman.h>
   9 #include <linux/smp_lock.h>
  10 #include <linux/notifier.h>
  11 #include <linux/reboot.h>
  12 #include <linux/prctl.h>
  13 #include <linux/capability.h>
  14 #include <linux/init.h>
  15 #include <linux/highuid.h>
  16 #include <linux/security.h>
  17 #include <linux/syscalls.h>
  18
  19 #include <asm/uaccess.h>
  20
  21 asmlinkage long sys_chown16(const char __user * filename, old_uid_t user, old_gid_t group)
  22 {
  23         long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
  24         /* avoid REGPARM breakage on x86: */
  25         prevent_tail_call(ret);
  26         return ret;
  27 }
  28
  29 asmlinkage long sys_lchown16(const char __user * filename, old_uid_t user, old_gid_t group)
  30 {
  31         long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
  32         /* avoid REGPARM breakage on x86: */
  33         prevent_tail_call(ret);
  34         return ret;
  35 }
  36
  37 asmlinkage long sys_fchown16(unsigned int fd, old_uid_t user, old_gid_t group)
  38 {
  39         long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
  40         /* avoid REGPARM breakage on x86: */
  41         prevent_tail_call(ret);
  42         return ret;
  43 }
  44
  45 asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
  46 {
  47         long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
  48         /* avoid REGPARM breakage on x86: */
  49         prevent_tail_call(ret);
  50         return ret;
  51 }
  52
  53 asmlinkage long sys_setgid16(old_gid_t gid)
  54 {
  55         long ret = sys_setgid(low2highgid(gid));
  56         /* avoid REGPARM breakage on x86: */
  57         prevent_tail_call(ret);
  58         return ret;
  59 }
  60
  61 asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
  62 {
  63         long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
  64         /* avoid REGPARM breakage on x86: */
  65         prevent_tail_call(ret);
  66         return ret;
  67 }
  68
  69 asmlinkage long sys_setuid16(old_uid_t uid)
  70 {
  71         long ret = sys_setuid(low2highuid(uid));
  72         /* avoid REGPARM breakage on x86: */
  73         prevent_tail_call(ret);
  74         return ret;
  75 }
  76
  77 asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
  78 {
  79         long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
  80                                  low2highuid(suid));
  81         /* avoid REGPARM breakage on x86: */
  82         prevent_tail_call(ret);
  83         return ret;
  84 }
  85
  86 asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid)
  87 {
  88         int retval;
  89
  90         if (!(retval = put_user(high2lowuid(current->uid), ruid)) &&
  91             !(retval = put_user(high2lowuid(current->euid), euid)))
  92                 retval = put_user(high2lowuid(current->suid), suid);
  93
  94         return retval;
  95 }
  96
  97 asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
  98 {
  99         long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
 100                                  low2highgid(sgid));
 101         /* avoid REGPARM breakage on x86: */
 102         prevent_tail_call(ret);
 103         return ret;
 104 }
 105
 106 asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid)
 107 {
 108         int retval;
 109
 110         if (!(retval = put_user(high2lowgid(current->gid), rgid)) &&
 111             !(retval = put_user(high2lowgid(current->egid), egid)))
 112                 retval = put_user(high2lowgid(current->sgid), sgid);
 113
 114         return retval;
 115 }
 116
 117 asmlinkage long sys_setfsuid16(old_uid_t uid)
 118 {
 119         long ret = sys_setfsuid(low2highuid(uid));
 120         /* avoid REGPARM breakage on x86: */
 121         prevent_tail_call(ret);
 122         return ret;
 123 }
 124
 125 asmlinkage long sys_setfsgid16(old_gid_t gid)
 126 {
 127         long ret = sys_setfsgid(low2highgid(gid));
 128         /* avoid REGPARM breakage on x86: */
 129         prevent_tail_call(ret);
 130         return ret;
 131 }
 132
 133 static int groups16_to_user(old_gid_t __user *grouplist,
 134     struct group_info *group_info)
 135 {
 136         int i;
 137         old_gid_t group;
 138
 139         for (i = 0; i < group_info->ngroups; i++) {
 140                 group = high2lowgid(GROUP_AT(group_info, i));
 141                 if (put_user(group, grouplist+i))
 142                         return -EFAULT;
 143         }
 144
 145         return 0;
 146 }
 147
 148 static int groups16_from_user(struct group_info *group_info,
 149     old_gid_t __user *grouplist)
 150 {
 151         int i;
 152         old_gid_t group;
 153
 154         for (i = 0; i < group_info->ngroups; i++) {
 155                 if (get_user(group, grouplist+i))
 156                         return  -EFAULT;
 157                 GROUP_AT(group_info, i) = low2highgid(group);
 158         }
 159
 160         return 0;
 161 }
 162
 163 asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
 164 {
 165         int i = 0;
 166
 167         if (gidsetsize < 0)
 168                 return -EINVAL;
 169
 170         get_group_info(current->group_info);
 171         i = current->group_info->ngroups;
 172         if (gidsetsize) {
 173                 if (i > gidsetsize) {
 174                         i = -EINVAL;
 175                         goto out;
 176                 }
 177                 if (groups16_to_user(grouplist, current->group_info)) {
 178                         i = -EFAULT;
 179                         goto out;
 180                 }
 181         }
 182 out:
 183         put_group_info(current->group_info);
 184         return i;
 185 }
 186
 187 asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
 188 {
 189         struct group_info *group_info;
 190         int retval;
 191
 192         if (!capable(CAP_SETGID))
 193                 return -EPERM;
 194         if ((unsigned)gidsetsize > NGROUPS_MAX)
 195                 return -EINVAL;
 196
 197         group_info = groups_alloc(gidsetsize);
 198         if (!group_info)
 199                 return -ENOMEM;
 200         retval = groups16_from_user(group_info, grouplist);
 201         if (retval) {
 202                 put_group_info(group_info);
 203                 return retval;
 204         }
 205
 206         retval = set_current_groups(group_info);
 207         put_group_info(group_info);
 208
 209         return retval;
 210 }
 211
 212 asmlinkage long sys_getuid16(void)
 213 {
 214         return high2lowuid(current->uid);
 215 }
 216
 217 asmlinkage long sys_geteuid16(void)
 218 {
 219         return high2lowuid(current->euid);
 220 }
 221
 222 asmlinkage long sys_getgid16(void)
 223 {
 224         return high2lowgid(current->gid);
 225 }
 226
 227 asmlinkage long sys_getegid16(void)
 228 {
 229         return high2lowgid(current->egid);
 230 }